This disclosure is related to the field of determining mechanical properties of a material and apparatus for making measurements for determining such properties. More specifically, the disclosure relates to automated apparatus that can make measurements corresponding to mechanical properties of materials using multiple values of measurement parameters to derive the mechanical properties.
A method known in the art for hardness measurement of a material sample is called “rebound hardness” where a projectile accelerated into a material sample and is bounced off the material sample. The projectile's energy loss during impact is used to produce a “hardness” index.
There are a number of devices known in the art to measure rebound hardness and at least one such device has been used to produce hardness profiles in rock core.
A related technique (indentation hardness) has been automated and integrated into an X-Y gantry system to map hardness variations in a material. Indentation hardness could be considered a simple version of a cone penetrometer. Indentation hardness measuring devices known in the art work on the principle that damage (inelastic deformation) to the material sample is produced by making the measurement, and that the amount of damage is used to determine a hardness index.